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This work proposes a method for actively constructing acoustic metasurface (AMS) based on the split hollow cuboid (SHC) structure of local resonance, with the designed AMS flexibly manipulating the direction of reflected acoustic waves at a given frequency range. The AMS was obtained by precisely adjusting any one or two types of structural parameters of the SHC unit, which included the diameter of the split hole, the length, width, height, and shell thickness of the SHC. The simulation results showed that the AMS can flexibly manipulate the direction of the reflected acoustic waves, and the anomalous reflection angle obeys the generalized Snell’s law. Furthermore, among the five structural parameters, the AMS’s response frequency band is widest with the hole diameter and height, followed by the length and width, and narrowest with the shell thickness. It is worth noting that comprehensive manipulation of two parameters not only broadens the response frequency band, but also strengthens the effect of the anomalous reflection at the same response frequency. The subwavelength size of the AMS constructed with such a comprehensive method has the advantages of a small size, wide response band, simple preparation, and flexible modulation, and can be widely used in various fields, such as medical imaging and underwater stealth.

In this paper, an asymmetric plasmonic waveguide structure is designed with a MIM waveguide and an oblique rectangular cavity, and its double Fano resonance characteristics and transmission properties are numerically investigated by the finite element method. The results show that double Fano resonances appear in the transmission spectra when the oblique rectangular cavity has different rotation angular θ . The double Fano resonances derive from different mechanisms, one of Fano resonances is induced by the interaction of horizontal and vertical resonance modes in the rectangular cavity, and the other is derived from rotating the rectangular cavity. So the Fano resonances can be easily tuned by the changing angle of rotation θ and structure parameters of rectangular cavity. Moreover, when the rectangular cavity is rotated to a certain angle, three Fano resonant peaks are appeared in the transmission spectra. The asymmetric plasmonic structure is also to detect the refractive index changes of the filled media inside of rectangular cavity and waveguide, which reveals a potential sensors application of the MIM waveguide with oblique rectangular cavity.

An analog of electromagnetically induced transparency (EIT) is investigated in a metal-insulator-metal (MIM) waveguide structure consisting of a stub waveguide and a side-coupled cross resonator. The transmission properties of this plasmonic MIM waveguide structure are numerically studied by the finite element method. The results show that there are double EIT-like phenomena as well as multiple EIT-like peaks in the transmission spectra by adding another stub. The transparency windows not only can be manipulated by changing the coupling distance between the stub and the cross resonator and the length of the horizontal and vertical cavity but also show a red shift with the increase of the refractive index n of the medium in the cross resonator. The designed plasmonic MIM waveguide structure is able to serve as a filter with a transmission rate of over 80 % and is easy to detect the refractive index of the filled media in the cross resonator, which indicates the potential applications in filtering and sensing.

A metal-insulator-metal (MIM) waveguide with double overlapping annular rings is proposed, and its transmission properties are simulated and characterized by the finite element method. The results show that the transmission valley appears in the transmission spectra when the straight MIM waveguide output port has a positional angular deviation θ relative to the incident port. Compared with the symmetric structure (θ = 0°), the filtering properties of the asymmetric structures (θ > 0°) are greatly improved. And compared to the MIM waveguide with single ring resonator, the filter characteristic of MIM waveguide with the double overlapping rings is superior to that of single ring resonator. For the asymmetric structure, due to the fact that parts of coupled MIM waveguide output port locates at the magnetic nodes of the standing waves in the ring resonator, there is a transmission minimum. Moreover, the asymmetric MIM waveguide can easily detect the refractive index changes of the filled media inside of resonator cavities, its potential applications in sensors.

The nonresonant extraordinary optical transmission (EOT) can achieve broadband transmission, which is significant for the collection and excitation of the broadband light. To obtain broadband transmission, in this paper, we proposed a subwavelength metallic circular nanohole arrays. The transmission properties of the metallic circular nanohole arrays were investigated using the finite element method. Results show that this paradigm structure can achieve broadband transmission. In addition, the effects of the polarization direction, the radius of the holes and the period of the arrays on the transmission property were also studied.

In this work, we present a novel facile electrodeposition approach to create micro/nano structure on an anodic copper plate with an alkali ethanol electrolyte solution. The electrolyte solution is composed of potassium hydroxide, potassium persulfate and ethanol. Hierarchical structures were formed on an anodic copper surface by an alkali assistant oxidation process, water immersion and fluorination, the as-prepared surface exhibits superhydrophobic property. The creation of morphological structures and chemical compositions on the treated surface was revealed by scanning electron microscopy (SEM) and X-ray diffraction techniques. The resulting surfaces composing of Cu(OH) 2 arrays demonstrates that water contact angle is as high as 165° and the rolling angle is less than 3°. The study is expected to create a new avenue for the basic research as well as real application.

We propose a novel metal–insulator–metal (MIM) waveguide structure consisting of a stub and a double side-coupled nanodisk. Its electromagnetically-induced transparency (EIT)-like response and transmission properties are numerically investigated by the finite element method (FEM). Numerical simulation results show that the EIT-like phenomenon appears in the transmission spectra. The transparency window can not only be manipulated by changing the radius of the nanodisk and the height of the stub, but also appear redshifted with the increasing of the refractive index n. Furthermore, the MIM waveguide structure is easy to yield a high sensitivity of 1200 nm/RIU with a figure of merit about [Formula: see text], which may be applied to nanosensors. These results would help us design the high-performance plasmonic devices based on the EIT-like response.